DE1283200C2 - Process and plant for the production of pellets - Google Patents

Description

The invention relates to a method and a method and plant for the production of pellets able to make pellets from powdery or

fine-grained moist material by rolling

a moving surface.

Usually the pellets by feeding 5 Patented be so far for:
powdery substances under a spray jet on Fritz Otto Wienert
a rotating device, ζ B a drum, produced, _{Nj Fa} " _N y _{(y St A)}
in which the mass rolls off and forms into small spheres, which are then used for further treatment.
will wear. It is difficult with this type of production. _ _ ,,, _ _.
rig to determine the size of the pellets, also need ^Dr - J ^{un Ε} · Ebbecke, lawyer,
Segregation and different moisture levels in 4100 Duisburg

individual pellets can be avoided, which

can easily arise during turning and rolling. ^ j _s Eifjnd _he namedThe desired grain size distribution is also at 15 ". _x ",. _ ^ '. _ " _{XT v ni Ci} . * Previous manufacturing processes cannot always be used - Fritz Otto Wienert, Niagara Falls, NY (V.St.A.)

keep. Often it comes to deposits of the damp

powdered raw material on the apparatus. With claimed priority:

the higher the pellet size, the less the V. St. v. America April 2, 1965 (445 051)

bring. ao

According to the invention, the moist, fine-grained

or powdery starting material first in a 2
Variety of shapes to plastic bodies from

about the same or slightly smaller volume than the shape does not need to bring the final pellets to be produced, in the shapes to have the shape of the pellets, which is jolted in almost densely packed moldings and difficult to emerge from the molds after spherical or elliptical pellets known way would make in Kontakt keiten, almost any with dry, fine-grained or powdery cross-sectional shape selected for moldings substitutes on smooth surfaces to round pellets, since the final shape is rolled in by rolling. 30 pits or grooves is generated.

A da on the shaking table or any other device equipped with an endless belt with corresponding openings or smooth surfaces can serve as a support for a multitude of shapes. From the position of the final pellet shape, the moldings are opened by means of pneumatic pressure (already pre-compressed moldings are applied, pressure) through rollers for further processing. 35 is the size of the resulting pellets uniformly

This type of production has the significant advantage that the internal structure of the pellets is also constant. Pellets of practically constant size and by allowing dry material to roll onto the roll-out mold, as the amount of surface area for each pellet is given before the moldings get on the allotted material by the size of the mold roll surfaces, the material of the shape can be determined will. In addition, each molding is already 40 pieces, even if they still have considerable moisture in relative terms before the production of its final shape, does not stick to the base. With the tightly packed, because the dry material in the mold is compacted by vibration when placed on the rolling surfaces. a coating can also be achieved on the pellets,

Appropriately, the briquettes on smooth, depending on the moisture level of the pellets and the rounded, z. B. with troughed areas, 45 amount of the additional material placed in back and forth movement. A segregation or less can be. The coating can consist of or the emergence of different moisture - the same material or a component of the grade in the different pellets will largely consist of pellet material, but can also be avoided because the material which differs from it on the points of the mold band is formed without a distributed mass greater movement into the molds 50 The briquettes can be introduced during the rolling and therefore have no opportunity to be moistened. Likewise, one can segregate during the process. Carry out a partial drying process.

909 634/225

The underside, which is used to moisten the starting material, is closed. At the same time, the liquid can be kept largely flat and by a binding agent or one with a called plate

Other liquid provided with binding agent. even. The plate 18 is next to the reversing drum 13

Pellets of uniform consistency and firmness supported on the console 29 and the platform 31, Even then, with the new method 5, which forms part of the frame 18. The plates 26 can be achieved if the starting material is strong and 27 are each vibratable by springs 32 and 34 different grain sizes and different supported and each with a vibrating device 33 and

Has grain size distribution. 35, e.g. B. an electromagnetic vibrator, By using shapes with larger or provided,

Corresponding pellets can be used in smaller volumes. Even distribution and indentation

different texture without difficulty of the mass in the forms of the band is made by the

be generated. Manifold 38 causes across the width

The ends of the upper run 14 used to carry out the method lie and come down to the edge. Iage is accordingly by a moving range. They are attached to the cross member 39 of Mold carrier with 15 elastic side plates 40 lying next to and behind one another is carried in a vibratable manner, Individual molds, a vibrating device and one which in turn are supported on the stage 31. One

known vibrating device for the distributor plates, which works with gas pressure or vibration, is at 42

Emptying device for discharging the moldings indicated.

from the individual forms as well as through a known mass in the forms of the upper run Rolling device marked. ao due to the constant vibration by means of the given-The mold carrier is useful as an endless belt if it is also designed for various vibrations formed, on whose upper run the filling device vibrating devices 33, 35 is attached on their conveying path for the molds, while on the lower run it seals and can then around the reversing drum 13 trum the emptying device acts. The forms hike over into the lower run 15. Usually Continuous openings in the endless belt, which adhere to the aj, the moist upper run generated by the shaking through support plates under the belt, enter the openings of the belt and must first are closed. As an emptying device, one can be loosened before it is discharged from the molds Serve pressure hood, which can be over the lower run of the belt.

is arranged and which is acted upon with a pressurized gas. For this purpose, a

is struck, which the briquettes down from 30 hood 46 is arranged. She is 47 with the hangers

presses. Instead of the pressure hood, one can be attached to the stage 31 and extends across it

Vibrating device step over a grate on the belt width. It consists of the upper part 49, the The lower run of the belt works. Side walls 50, the end walls 51 and the partition

The invention further relates to the formation of the walls 52, which also extend across the lower run Rolling device as a reciprocating Schüttet- 35 extend. The lower edges of the wall are elastic, in particular as a table with sealing strips 54, which are elastically mounted in the longitudinal direction, and have rounded grooves running in front. The task - preferably made of rubber. The chambers created by the separating device for the additives are arranged above the wall 52 with a pressure shaking table at its end. air or with another pressurized

With reference to the drawing of an embodiment 40 gas or steam from the line 58 over the with

for a system for performing the described valve-provided branch lines 59 applied,

When driving, there are further peculiarities, training, and the lower run 15

discussed possibilities and advantages of the invention. supported by a grate 61, the elastic of

Fig. 1 shows the entire system in side view; Springs62 on the stand63 of the frame 18 F i g. 2 gives a cross section along the line 2-2 45 will bear. The grate 61 is preferably (A b b. 2)

in Fig. 1 again; slightly wider than the band H and with a multitude

Fig. 3 shows a detail of the ejection device provided by parallel slots 64 which extend in longitudinal

processing for the briquettes; direction over most of the grate.

4 and 5 show different configurations. The slots 64 coincide with the different bait shapes in the mold carrier. 50 tons of molds 23 in belt 11 together. Included

According to Fig. 1, an endless belt U is on the Schlitz64 boards than the diameter of the Drive drum 12 and reversing drum 13 are guided, shapes, and their walls expand downwards the upper run is conical at 14 and the lower run at 15. The grate 61 can also be marked with a vibration. The tape rests in bearings equipped by the devices, e.g. B. the electrical supports 16, 17 of the frame 18 are carried. The 55 magnetic vibrators 65. The belt is driven by the motor 21 via a worm gear. Between the uprights 63, a vibrating or other gear mechanism 20 extends in motion vertically 67 in the longitudinal direction under the strand 15 and the belt grate 61 starts moving in the direction of the arrow. The shaking table is driven by a drive 68 puts. reciprocated and rests

In volume U, according to FIG. 2 to 5 forms 23 60 elastic supports 69, which, like the drive 68

introduced, preferably carried by the frame 18 from above. The table 67 is

continuously below. These openings are inclined from the (Fig. 1).

Filled feed hopper 24, which forms across the As best seen in FIG. 2, forms Width of the tape extends. The applied form the surface of the shaking table 67 a series of smooth,

Access material 25 for the pellets is distributed evenly over 65 parallel longitudinal grooves or grooves 71. They lie vertically

the entire width of the upper run 14 distributed and in kai under the slots 64 of the grate 61, so that a

the openings 23 introduced. They are made by the bodies falling through the slots 64 in the associated

aneinaniter 'subsequent support plates 26, 27, 28 is caught on rigen groove.

The end wall 72 of the table 67 closes the channels or grooves 71. Below the left end of the The receiving funnel 73 is located on table 67.

The nozzles 75 and 76 are above the shaking table 67 through pipelines to S, not shown Gas or liquid sources connected. The sieve 77 above the table 67 is suspended from the cross member 79 by means of the spring arms 78 and can through the vibrator 80 can be made to vibrate. A feed distributor 81 also feeds the sieve 77 fine individual particles of existing substance that are evenly abandoned across the width of the table 67 will. Above the shaking table 67 at its right end (Fig. 1), a powder distribution device 83 is provided to the grooves or channels 71 with to supply powdery substance.

The following example illustrates the use of the functions shown in FIG. 1 and 2 shown plant for carrying out the new pelletizing process.

ao

example 1

A plastic mixture is formed from 100 parts Brazilian Hämatiterzes and 9.5 parts of a 10 ° / _o aqueous sodium silicate solution. The ore contains considerable amounts of both coarse and fine particles, and the sieve analysis is as follows:

24.1% jfrom 0.833 mm to 0.417 mm sieve openings 12.3 ° / ₀ from 0.417 mm to 0.147 mm sieve openings 2.8% from 0.147 mm to 0.104 mm sieve openings 5.0 ° / ₀ | _nin . up to 0.074 mm I ₀ . ..., «. 55.8 "/ Ij ^{from 104 mm} to _{0.074 mm} ) sieve openings

30th

The plastic mass is transferred from the feed hopper 24 onto the rubber band running in the direction of the arrow given up. As it passes under the distributor plates 38, the plastic mixture is pressed into the molds 23 of the band U. The forms have approximately the same volume as the desired pellets. The filling of these forms is made possible by the Vibrating the moving belt by means of the support plate 26 and vibrating the distributor plates 38 promoted.

A further vibration of the belt 11 by the support plate 27 leads to the compression of the molding compound, which is caused by the leakage of liquid the surfaces of the body become recognizable.

To remove the briquettes from the molds, the belt with its lower run 15 is over the Vibrating grate 61 passed. The jolting motion thus transmitted to the belt makes it proportionate The moldings are easily removed from the molds by gas pressure from the hood 46 arranged above the Rqst 61 to eject. Normally an air pressure of around 250 mm water column is sufficient.

The moldings of about 1.7 cm in diameter and 1.4 cm in length fall through the slots 64 of the grate 61 into the corresponding grooves 71 of the shaking table 67, in which they are rolled back and forth and thereby rounded into pellets. A reciprocating motion of the table of about 7 cm per Va second is usually sufficient to achieve a good rounding before the pellets exit the bottom of the table. Additional fine hematite ore, the / ₀ a Tyler sieve with 0.074 mm openings clear happens to 91.2 °, is through the manifold 83 scattered thinly in the grooves 71. Take the pellets during a shaking period of approximately 6 seconds this fine substance on the surface as a coating.

about 11 parts of hematite per 109.5 parts of the original mixture in such coatings contained in the pellets of this batch. After drying, the pellets each weigh about 15 g and have a diameter of about 1.8 cm.

Example 2

A plastic mixture is formed from 79 parts of chrome ore, ground so finely that it _{passes 90 ° / 0} through a sieve with 0.043 mm clear openings, and 21 parts of baking coal, ground so finely that it is 100% a sieve with 0.074 mm clear openings happened, and 27 parts of water containing 1 part of dissolved soda waterglass.

This mixture is poured into the molds in belt U and shaken to compact. After removal from the molds by air pressure in the Hood 46 and after shaking the briquettes are rolled in the grooves of the shaking table 67, which with additional powdered coal can be charged while warm air is blown over the table. In this way, the briquettes are rounded into pellets and take up about 2 parts on the surface Coal per 100 parts of ore-coal mixture used as concentric shells.

The pellets that are obtained are about 1.8 cm in diameter. They are strong enough not to break during treatment.

In the preceding examples, aqueous liquid binders are used. However, others can Liquid binders, such as B. oils, thin tars and tall oils, or solid binders such as clay, be used together with a suitable liquid to make a plastic cohesive Get mass. This is explained in the following examples.

Example 3

From 57 parts of limestone, ground so that it passes through a sieve with 0.147 mm clear openings 19 parts of clay, ground so that it passes through a sieve with 0.074 mm clear openings, and a plastic mixture is formed from 16 parts of water.

This mixture is poured into the molds and shaken. The moldings are after pressing from the molds by rolling in the grooves of the shaking table, in which a thin layer of finely powdered limestone is created by the feed device 83 is applied, shaped into spheroidal pellets. The pellets thus obtained are well shaped and have a smooth, non-sticky outer surface.

It may be desirable to increase the length of the shaker table used to round the pellets extend to higher belt speeds without over-filling the grooves or troughs of the Allow tables with pellets. In such cases, as shown in FIG. 3, the shaking table 86 can be at an angle, preferably an angle of 90 °, to the direction of movement of the belt 11 are arranged. The moldings are divided into chambers from the openings 23 by air, which is arranged under pressure of the angular position Hood 88 is fed, pushed down and distributed in the troughs 87 of the table 86, to be rolled there.

The shapes in the band or other shape carriers can have different sizes, cross-sections and heights as required and also different

Claims (14)

7 8 experienced training. The forms 91 in volume 11 knew of water-soluble binders, such as. B. strength, according to F i g. 4 have a conical design so that glue and other cellulose derivatives can be used to facilitate ejection of the moldings. In many cases, a binder is unnecessary, and further, as shown in Figure 5, in molds 23, most no more than about 0.2 to 1% on bushings 92 of any desired and convenient dry basis in the pellet is required. It remains free size and shape made of any suitable material, the binder can be used in a solid or liquid. Add silicon rubber or fluorocarbon form. StorTpolymers may be desirable for such bushings - for the removal of the pellet body from their be worth, since such materials have a non-adhesive form, the vibration is not always necessary, since surface and thus the removal of the io often the gas pressure alone in the hood 46 is sufficient, Make moldings easier. To push out the moldings by changing the book. In most cases Different pellet sizes can be achieved. air is preferred for pressing out the moldings, When the molds wear out, the bushings can become active, but steam, nitrogen, carbon dioxide can also be used can be changed times. and other gases or vapors are used. The tape will be endless and made of rubber or will become »5 best results when rolling the molds achieved another suitable elastic material when the soles of the grooves or troughs one represents the shapes are regular in a multi-radius of curvature τ according to the equation number of rows and columns arranged the (2r ) 3 Shapes in some columns or rows can be V = different in size and / or formation of μ " those in other rows or columns. where V is the volume of a single pellet The vibrating device for the distributor plates 38. A larger or smaller radius can cause an EUipsen- and / or the support plates 26 and / or 27 can form the pellets. The mode of operation of some applications is omitted. In some cases the shaking table changes with the size of the pellets, may have less shaking or vibration, or as the raw materials used and other factors. Tapping may be necessary to create a tight cluster. Usually, the time is right to achieve satisfactory roundness in the molds. Likewise, mechanical molding in the range of about 5 to 15 seconds see press-in devices, such as fingers or pins, can be used for molded articles with a rigidity according to Example 1, which rub the starting material into the molded articles when rolling on the holes of the tape or press in. 30 shaking table by touching fine dry Essentially any particulate powder material can be a coating. Since this excess raw material has a drying and stiffening effect by means of the new process by means of a liquid and, in some cases, a means of the thickness of the coating, which can be formed into pellets without further treatment. To the extent that can be achieved, limited. When one lot of pellets according to the invention useful 35 a thicker coating is desired to obtain, can be raw materials include magnetite and Erzkonzen- in known manner, a suitable liquid with Uttte _a ilmenite _t alumina _l silica-alumina mixtures, additional binder through the nozzle 76 the silica-coke mixtures, iron oxide-carbon-PCI ^lpf s ^ sprays and finely divided powder from the mixture and magnesia. Even if the best results vibrating sieve 77 are sifted on them. It can then be achieved as soon as the deformation to 40 naturally also proceed in the same way in order to apply a substance for the dense addition of the pellets outer coatings, which has a different aggregation favorable grain size distribution, to the pellets. On the other hand, this leads to the process being valuable even with unfavorable grain bubbles, warm air or some other suitable size distribution, since in many cases un-gas over the table through the nozzle 75 leads to the possibility of pellets at all by another ver - To dry 45 surfaces of the pellets and make the opening as described herein. take dry, powdery substance to consume The liquid phase of the plastic mass, from diminish,
In the examples, the amount of rounding of the moldings should exceed the amount described by the mass of the particles on a shaking table. It can be absorbed even when packed tightly. The so turntable or rotating drums as rolling devices excess can be used about Vi ^{up to a} maximum of 20%. In general, however, one achieves the amount. The leakage of excess liquid with the most constant and satisfactory results during the shaking of the molds is, as mentioned above with a shaking table, a sign of the achievement of dense agglomeration of the particles. The time required for the shaking 55 that the new process for the production of spheroidal production depends on the intensity of the pellets made of fine-grained or powdery raw oscillation and on other factors such as the substance is effective, practical and adaptable. structural design of the apparatus and it can take a wide variety of different raw materials from the amount of excess liquid present. are used, and the pellets Ki-Concerning made of the latter factor is of the typical 60 nen different structures and features have noted that the required vibration time to be more Herein listed parts and percentages, as a 100% increase when the when in the working process nothing else is indicated, based on the weight of Example 1, only 9 parts of aqueous silicate solution were used. instead of 9 , 5 parts. Patent claims: As mentioned above, a soluble 65 Silicate a clay material, such as bentonite, and other 1. Method of making pellets from known substances are used as binders, powdery or granular, moist material when a binder is desired. Others move by rolling on a moving surface, the characterized by the moist starting material initially in a variety of Shapes into plastic bodies of roughly the same or slightly smaller volume than the ones to be produced Pellets brought, compacted in the molds by shaking and after being discharged from the Forms in a known manner in contact with dry, fine-grained or powdery additives is rolled into round pellets on smooth surfaces. 2. The method according to claim 1, characterized in that the moldings by pneumatic Pressure can be applied from the molds. 3. The method according to claim 1, characterized in that the moldings during rolling be re-moistened. 4. The method according to claim 1, characterized in that the moldings during rolling be partially dried. 5. The method according to claim 1, characterized in that the moldings on a smooth aus- ao rounded surface, for. B. troughed surface, are set in a reciprocating motion. 6. The method according to claim 1, characterized in that the liquid used to moisten the starting material is a binder or as a liquid mixed with a binding agent is used. 7. Plant for carrying out the method according to one or more of the preceding process claims, characterized by a movable mold carrier (11) with individual molds (23) lying next to and behind one another, a vibrating device (33, 35) and an emptying device in which by being pressurized Gases and / or vibrations (65) are used to remove the moldings from the individual molds in a manner known per se, as well as by means of a known rolling device (67). 8. Plant according to claim 7, characterized in that the mold carrier (11) is designed as an endless belt, on whose upper run the filling device ( 24, 38) for the molds is attached, while the emptying device (46, 65) acts on the lower run 9. Plant according to claims 7 and 8, characterized in that the molds in the endless belt (14) form through openings which are closed in the upper run by support plates (26, 27) under the belt. 10. Plant according to claims 7 and 8, characterized in that a pressure hood (46) is used as the emptying device, which is acted upon by a pressurized gas and is open to the side of the lower belt strand (15). 11. Plant according to claims 7 and 8, characterized in that the emptying device is a vibrating device (65) which acts on the lower belt strand (15) via the grate (61). 12. Plant according to claim 7, characterized in that a reciprocating shaking table (67) is used as the rolling device. 13. Plant according to claim 12, characterized in that the shaking table (67) is provided with rounded grooves running in the longitudinal direction. 14. Plant according to claim 7, characterized by a feed device (83) for the additives at the end of the shaking table (67). For this purpose 2 sheets of drawings